Portable Digital Multitrack Recorders

Roland's VS1680 is currently the only all‑in‑one digital multitracker to offer 16‑track recording, and also provides other nice features such as mix automation and the superbly detailed display.

With almost 20 self‑contained digital multitrackers on the market, either new or second‑hand, it can be hard to decide which one is for you. Debbie Poyser & Derek Johnson discuss the options and round up the available models.

The analogue cassette multitracker has been a stalwart of the home studio for almost 20 years, but it now seems apparent that its days are numbered — except, perhaps, at the ultra‑budget end of the market — and that its digital counterpart will eventually replace it. At least 18 digital multitrackers, from a variety of manufacturers, have been released since the end of 1995, recording to a range of media and offering between four and 18 tracks. Models are now available to suit almost every need, from the basic songwriters' 4‑track notepad machine right up to the self‑contained 18‑track digital album‑production studio, complete with CD mastering facility. Prices, too, run the gamut from £399, as cheap as many cassette multitrackers, to over £2000.

Pros & Cons

Korg's D8, like digital multitrackers from Roland and Akai, has a digital mixing stage, and records eight tracks without data compression.

There's no doubt that digital multitrackers can offer considerable advantages: first, and most obviously, there's the much improved sound quality over cassette recording — no tape hiss, no wow and flutter, and an increased frequency response. There's no waiting for tape to fast forward and rewind. And, unlike cassette multitrackers, you don't need to give up a track to recording sync code if you want to synchronise a sequencer to your recorder — digital units can directly transmit timecode information to drive a MIDI sequencer. Some digital multitrackers stretch their apparent number of tracks still further with 'virtual' tracks. Though virtual tracks take up disk space like any other track, this feature allows the user to record multiple takes and assign just the chosen ones to 'real' playback tracks, giving much more flexibility and choice in the recording process. Digital audio editing, at its most basic featuring such operations as cut and paste, also adds to the appeal of much of the new wave of personal multitrackers, as do song naming, the presence of Undo routines, digital outputs for direct mastering to DAT or other digital mastering medium, and digital inputs for easy interfacing with a growing number of modern synths, samplers and effects processors. Some digital multitrackers even transmit MIDI data from all their physical controls, giving the potential for sequencer‑controlled dynamic mix automation, and some offer built‑in effects or optional effects boards, adding even more to the convenience of the package. There's no need to worry about heads wearing out, and no cleaning and de‑magnetising of heads before every recording session, as with cassette multitrackers. Word from our professional servicing community spokesman Mike Swain, of service centre Panic Music, is that hard disk multitrackers are actually more reliable than analogue, as there are few moving parts to go wrong, and that while Minidisc multitrackers can be more problematic than hard disk recorders, they certainly are no worse than analogue.

On the flip side, the cost of digital recording media is higher than cassette. Even Minidisc multitrackers work out more expensive in terms of media costs than cassette models: the special data‑format Minidiscs these machines need cost around £15 and have a capacity of 37 minutes of 4‑track data‑compressed audio — compare that with the price of even the best‑quality cassettes. With hard disk, one also has to take into account the need to back up audio (see the '#Backing Up' section and Martin Walker's 'https://web.archive.org/web/2015...' article from SOS February 99).

There are one or two other issues to bear in mind, too: some digital multitrackers can be more complicated to operate than their analogue counterparts, with menu systems and digital synth‑like parameter access. Hard drives can also create unwanted mechanical noise in the studio environment, and can become fragmented with use. Note that not all machines offer defragmenting routines; disk access problems that would normally be cured by defragmenting require you instead to offload all your audio (to the backup device you purchased!) and re‑format the drive to achieve the same goal.

Considering the above pros and cons, many people will conclude that the advantages of digital multitrackers outweigh their shortcomings by quite a margin, especially those who are looking for more than a basic notepad and would hope to take their recordings to full master status for CD production. Sound On Sound staff receive more and more calls from readers uncertain as to whether to go digital, and which model best suits their needs — which is why we've put together this buyer's guide. We've included discontinued models in the guide, as none are more than four years old and they are likely to be easily available second‑hand — and, in some cases, software‑upgradeable to current or near‑current specifications.

Recording Media

The latest addition to Yamaha's range of Minidisc multitrackers, the MD4S, is a competitively priced 4‑track.

Three types of recording media are used by the machines in this guide: fixed hard drive, removable hard drive (such as https://web.archive.org/web/2015...), and data‑format Minidisc. Most of the machines in the guide that record to hard disk have SCSI, so any suitable SCSI drive will be be usable. The manufacturer of the recorder should be able to advise on recommended drives (and in the case of recorders that don't come with a supplied drive, will fit a drive for you, if desired). Note that (fast) AV drives are advisable for digital audio recording, and that not all the machines in the guide will record to Iomega Zip drives.

There's not too much to say about Minidisc, because it's very straightforward. The things to bear in mind here are that Minidisc audio is always data‑compressed (because it wouldn't otherwise fit on the disc) to the tune of about 5:1. Storing audio on a Minidisc is cheaper, minute‑for‑minute, than on hard drive; the trade‑off is that it is compressed and that recording time is quite limited. Other advantages of Minidisc are that the discs are removable and convenient for storage, just like cassettes, and that very little mechanical noise is produced by a Minidisc transport.

How Many Tracks? This might seem a rather obvious consideration, but with digital things are not always exactly what they seem, quite apart from the fact that a machine may offer 'virtual' tracks alongside its playback tracks. The machines currently available provide four, eight, 12, 16 or 18 tracks, so if you're looking for a notepad you might be tempted to consider only the 4‑track options. However, bear in mind that your requirements might grow in the future.

In many cases there is also a trade‑off between the number of tracks used, or available, and recording time (see next section) or sound quality. For instance, the only machine which currently offers 16‑track recording, Roland's VS1680, does so by virtue of data compression (see box, right), which has a slight, but to some people noticeable effect on sound quality. If you want uncompressed audio, you can only record eight tracks of it.

A corollary to how many tracks a machine has is how many can be recorded simultaneously. Often you can't record to the full track complement at the same time, and if you want to work in a 'band' context, with lots of people playing together, and you want a separate track for each of them, this is obviously an issue. A couple of machines will allow more tracks to be recorded simultaneously via a digital interface than via the analogue inputs — Fostex's FD8, for example, can record all its eight tracks simultaneously via the ADAT interface but only two at the same time through its analogue inputs.

...many people will conclude that the advantages of digital multitrackers outweigh their shortcomings by quite a margin...

Recording Times

Sony's MDMX4 is a well‑specified Minidisc 4‑track.

With a cassette multitracker, the only parameters relevant to recording time are the length of the tape and the speed at which the transport is running. A 60‑minute cassette running at double speed will yield 15 minutes of recording time, whether the recording is 4‑track, 6‑track or 8‑track (cassette multitrackers use both sides of the tape at once, so only 30 minutes is available, reduced to 15 at double speed).

When it comes to hard disk recording, things are rather more complicated. For a start, recording time will vary depending on the size of the disk attached. In addition, time for each track has to be accounted for separately (eight tracks of audio take up more HD space than one). Many machines offer multiple sample rates, and audio recorded at 32kHz, for example, will use up less space than audio recorded at 44.1kHz. Obviously, machines that use data compression can also be more economical on disk space than those which only do uncompressed recording. Some machines even offer a variety of recording modes which mix higher and lower sample rates with different ratios of compression, yielding several recording times for the same size of disk. With the Roland range, different compression ratios and lower sample rates can be used for very long recording times, if desired. Virtual tracks have an impact on recording time, too, since these are stored on disk just like any other track.

Dynamic allocation of recording time is yet another consideration. Machines which allocate recording time dynamically treat the available disk time as a pool: if you don't have continuous audio recorded on some of your tracks, the time between the audio that is recorded remains in the pool, to be used later. In the case of machines that don't allocate recording time dynamically, the same fixed amount of time will be available per track regardless of how much of it you use for individual tracks.

Because the question of how much recording time will be available with a given machine is so variable, there's no line in the table for this issue. See the '#Calc Rec Times' box for some guidelines to apply when working it out for yourself.

When checking out the different machines on the market, see what limitation is placed on disk size, as this restricts the total recording time available. If you chose to record to Zip drive, for example, as some of the machines in the guide can, you'd be limited to 100Mb per song (250Mb with the forthcoming Roland VS840EX, which uses the new Zip 250 drive), and this doesn't go that far when you're talking about 4‑ or 8‑track full‑bandwidth uncompressed audio. Fostex's FD4, for example, offers 17 track minutes of full‑bandwidth recording on one Zip cartridge, and if this is divided between four tracks of continuous audio it comes to little over four minutes, which is only OK if you're doing classic pop songs! Fairly respectable times can be achieved from Zip with those machines which use compression, however, such as the FD4 in its compressed mode, and the Roland range. Zip can also be quite cost‑effective, given that cartridges can be bought for as little as £5 each if purchased in bulk.

Even if you're not a fan of digital recording there are features of the technology that you'll really appreciate.

Disk partition size can be significant too: the Roland VS880EX, for example, can use hard drives of up to a maximum of 32Gb, but the biggest partition size it can address is 2Gb (and you can't record past that point on a single song). If you were using uncompressed mode with a lot of virtual tracks on a very long piece of music, there's a remote chance you could run out of partition space!

Virtual Tracks & Digital Editing

The DPS12 from Akai records 12 tracks to either a fixed 4.5Gb internal hard drive or an Iomega Jaz removable hard drive.

Even if you're not a fan of digital recording there are features of the technology that you'll really appreciate. The ability to cut, copy and paste audio digitally saves time and retains quality. How the various machines handle these basic digital audio manipulations varies.

Many of the machines that record to hard disk do not employ the most space‑efficient type of editing — playlist editing — wherein if you want to copy a chorus from a song, say, the machine simply remembers the start and end point of the chorus and references it for playback at whatever position in the song you require. They instead physically copy the required data, with every repeat using up more disk space. The Minidisc recorders, however, all use this form of editing, which enables very easy remixing of the order of a track.

MD multitracks have some other nice tricks of their own, even though they don't have virtual tracks. For example, all of them allow 'bouncing' into stereo even where all four or eight tracks are used (a feature shared, incidentally, by Fostex's DMT8VL and FD4). In the case of Yamaha's MD models, two of the original tracks are given over to the bounced audio, so their original content is overwritten, while the Tascam 564 allows four tracks to be bounced forward to a location further on in the disk, leaving the four original tracks untouched.

Mixer Facilities

The ground breaking DMT8 from Fostex was the first digital implementation of the portable multitracker concept.

The machines surveyed in this roundup are all‑in‑one, or 'portable' multitrackers, which means that (unlike, say, an ADAT) they have a built‑in mixer enabling them to be used without an additional mixer. These built‑in mixers range from fairly simple stereo ones, as found on Fostex's FD8, through the cassette multitracker type found on the MD‑based machines, to the pretty sophisticated digital mixing surface with multi‑layered controls built into Roland's VS1680. If there's a downside to many of the machines featured in this guide, it's that the built‑in mixers are often rather limited compared with stand‑alone mixers.

Insert points, for example, which you'd hope for to facilitate dynamics processing with your favourite devices, are often not fitted. The units that do include inserts only have them on a couple of input channels, and never on the master outputs. Where XLR mic inputs are available, they hardly ever offer the phantom power required to operate condenser microphones.

Auxiliary sends are important for those wishing to patch in additional effects units, and it's a little disappointing that none of the multitrackers offer more than two, though this is less important in the case of those models which offer built‑in effects. Particularly vexing is the way in which some multitrackers with two aux sends have both sends sharing a single pot! Turn left for aux send 1 and right for aux send 2: you don't have to be a rocket scientist to know that you'll only be treating your mix channels to one effect each.

EQ is provided on all the models in the guide, but varies quite a lot in its complexity; some offer 2‑band, some offer 3‑band, and some provide at least a swept mid band too. In the case of some machines (the ones with digital mixers), be aware that EQ often shares processing resources with other functions, so EQ sophistication can vary depending on what else the machine is being asked to do.

Most of the mixer sections, however, are analogue, meaning that bouncing down audio involvessending digitally recorded material through analogue circuitry, which is a shame. The exceptions are the Akai DPS12, the Korg D8 and the Roland range, which have digital mixers.

One way to ensure that a digital multitracker has enough flexibility to grow with you is to choose one which has direct track outputs. These allow tracks to be routed to an external (possibly better‑specified) mixer.

Effects

Built‑in effects are obviously a very attractive option for many people, and are available with several of the machines in the guide (those with digital mixers), either as standard or as an optional board. The Roland VS range started out offering an effects board as an option, but this was so popular that Roland soon decided to sell their first machine, the VS880, only with the effects board included. They now include effects as standard on all their new machines, with the option to add more in the case of the VS1680, which has one dual stereo effects board fitted and room for another to be installed. Even where an effects board is an option, as in the case of the Akai DPS12's dual‑processor board, retailers will often bundle it with the recorder at an attractive price. Built‑in effects do vary in sophistication, with the VS1680 offering the most scope and those on Korg's D8 (based around their Pandora stand‑alone guitar‑orientated processor) possibly the most basic.

Interface Issues

We're discussing a digital recording medium here, and it's understandable to wish to interface other digital equipment with a digital multitracker, and certainly to master straight to DAT or other digital mastering medium. Most of the machines discussed offer digital ins and outs, usually S/PDIF optical in format. This can present a slight problem when it comes to interfacing with common DAT machines, which usually have co‑axial connections, and would require a converter box such as Fostex's COP1. The Roland range is the exception to the rule, being provided with co‑axial connectors at least, and on some models both optical and co‑axial. The Fostex FD8 also deserves special mention, as it features an ADAT interface which allows it to integrate with other ADAT‑equipped gear. Indeed, an FD8 owner who had outgrown its fairly basic analogue mixer could add an ADAT‑equipped digital desk and access the 8‑track recorder section direct.

Though the computer world seems to be moving to new, faster standards of data transfer, for now SCSI is the interface which will be familiar to most. Nearly all non‑MD‑based multitrackers have SCSI built‑in, or the ability to add it later. The interface can be used to connect a main recording drive, or additional drives for more recording time or backup.

Automation & MIDI

Mix automation is a great facility to have and can make very sophisticated recordings much easier to accomplish. Only those units with digital mixers offer automation, and the type varies. The Akai DPS12, for example, transmits MIDI controller data when its physical controls are moved, which can be recorded into a MIDI sequencer for later playback. The Korg D8 automates in a more basic way (but doesn't need an external sequencer), using internal 'scenes' or snapshots of mixer status which can be changed automatically during a song. The Roland units (with the exception of the VS840/VS840EX) can be automated via MIDI and also have a built‑in dynamic automation mode.

All the machines in the guide have MIDI sync capability, and will transmit, receive, or transmit and receive MIDI Clock and MIDI Timecode (MTC). A couple, however, only transmit at (or sync to) a fixed rate of 30fps, so watch out if this is important to you (if you work to picture, for example). Most are MIDI Machine Control compatible, so that so that their transports can be controlled remotely, from a MIDI sequencer. The exception to this rule is the Yamaha MD4.

Backing Up

When it comes to digital recording, backing up is essential — it's said that no digital data exists until it's in at least two places! Digital media haven't been around long enough for us to assess their reliability in the really long term, and often when digital data does become corrupt it's not even partially retrievable. Contrast this with analogue tape, which can usually be played even if it's getting on a bit and suffering from dropouts and so on.

However you do it, backing up is an issue from day one, and in the case of machines that record to hard drive, will be much easier with the benefit of a SCSI interface. This should allow the connection of external drives, whether fixed or removable, for backup purposes. Note that the Fostex FD4, although it has a SCSI interface, only recognises one SCSI device, rather than the usual SCSI limit of seven. The only way to back up via SCSI from the FD4 would thus be if you had the optional internal 1.4Gb IDE drive fitted for recording and attached an extra drive to the SCSI port for backing up.

When it comes to digital recording, backing up is essential — it's said that no digital data exists until it's in at least two places!

Many of the units here offer DAT backup via their digital connections (and Fostex's first‑generation DMT8 can only back up data in this manner). DAT backup is slow, but more cost‑effective than removable hard drives: you'll probably have a DAT machine for mastering anyway, so all you need is more tapes (and time!). A few units (from Roland, and with a recent software update the Akai DPS12) even offer the option to back up data to CD‑ROM if you have a suitable CD burner, as they have CD‑writing routines built in. This would seem to be a very good option.

The issue of backing up is a bit of a head‑scratcher in the case of the Minidisc multitrackers: as far as we can see, you can't back up at all with these machines — though the same applied to cassette multitrackers, of course.

Go Test!

Though different models vary quite a lot in sophistication, very good results can be obtained from any one of the digital multitrackers currently on the market — including the early models available second‑hand, though these can be limited in some ways. Hard disk is certainly more flexible than Minidisc, but Minidisc has simplicity and convenience on its side, plus playlist editing. In addition, for anyone on a small budget, recently discontinued Minidisc 4‑track models still in plentiful supply make excellent bargains at the moment, with reductions of up to 50 percent on original retail prices. Now could be the time to go get a test drive of your chosen machine and go digital!